super easy

Four

Ay que la madre .-. This is he easiest question known to man, just like 2+2 but it's simple multiplication.
2*1= 2
2*2= 4
2*3= 6
2*4= 8
2*5= 10
2*6= 12
2*7= 14
2*8= 16
2*9= 18
2*10= 20............and so on ! -.- Now I have a headache....lol